Campbell Soup has begun the process of selling off a number of its brands, including its Arnott's cookie and crackers business, as it looks to pay down the debt left in the wake of its acquisition of Snyder's Lance earlier this year, people familiar with the matter tell CNBC.

Campbell has sent out materials to tease the sale of its Australian Arnott's biscuits business and Kelsen baked snacks that could fetch $2.5 billion to $3 billion from buyers. The biscuit and cracker maker is the largest in Australia and has therefore caught the eye of a number food companies that are eyeing global expansion as challenged U.S. grocers continue to exert their pressure.

Food companies — including Oreo-owner Mondelez, Kraft Heinz and Ferrero, which owns Nutella — are among those eyeing the business, the people said.

Snacks have become increasingly important for food companies to buy as more and more people eat on-the-go and sales of grocery staples, like cereal, have slowed. In the U.S., though, there are few brands available to buy to move the needle for companies that generate billions in annual sales.

Arnott's gives buyers a chance to buy a large business in an established market. Still, with Australia relatively isolated, it would also likely require a buyer with an existing global footprint and may also limit their ability to expand the brand further into other international markets like China, say people familiar with the industry.

Campbell expects to sign non-disclosure agreements for its international snack business in the next weeks, and will then begin to send out confidential materials, the people said. This will launch a formal sale process. While such processes take weeks, it remains possible a keenly interested party could expedite it by lobbing in a particularly high bid, some of the people said.

One likely consideration in the sale process is potential anti-trust issues due to Arnott's hold on the Australian cookie market. Campbell is under pressure from activist investor Dan Loeb and his hedge fund Third Point, which have chastised it for poor performance, making it unlikely it will want to take on much risk that antitrust authorities could oppose a deal.

Meantime, Campbell has also started to sell its Garden Fresh business, which it bought for $231 million in 2015, some of the people said. The soup company previously said it is selling fresh food brands including carrot and smoothie company Bolthouse Farms, which it bought for $1.55 billion for 2012. It is looking at selling the two separately to see if it can expedite that process, the people said.

The people requested anonymity because the information is confidential.

Thomas Hushen, a spokesperson for Campbell, said the company does not comment on rumors or speculation. Hushen said Campbell expects its global snacking business "will be attractive to many different types of buyers because of its strong brands and position in the market."

Hushen added that the company is "focused on completing this transaction in a timely and disciplined manner that maximizes value."

Mondelez, Ferrero and Kraft Heinz all declined to comment.

The sales come as Campbell looks to unwind efforts to broadly diversify beyond its iconic soup business and pay down the debt left behind from its $6.2 billion purchase of pretzel and chip company Snyder's-Lance. The deal more than tripled Campbell's debt burden.

The soup company is also under pressure from Third Point which, until Friday, had been trying to remove all of Campbell's 12 directors. It is now only looking to replace five, implying it has been facing investor push-back. Late last month, Campbell delivered a significant blow to Third Point's campaign with heirs to the founder that hold roughly 41 percent of the company's shares supporting the soup company over Third Point.

Campbell's interim CEO, Keith McLoughlin, said Campbell had proposed adding two of Third Point's nominees to its board after the company's annual meeting, Kurt Schmidt and Sarah Hofstetter, according to a statement released Friday. McLoughlin said Third Point rejected that option.

"We believe it is important for all of our shareholders to know that we are offering to add two new independent directors, Mr. Schmidt and Ms. Hofstetter, from the Third Point slate, as we continue to refresh our board," McLoughlin said.

Third Point did not immediately have a comment regarding McLoughlin's latest statement.